Help with 4l80e Build

[Rsoup]

So thanks in advance to any help I can get from the knowledgeable people on the forum! After being jerked around by some “reputable” shops I’ve decided to rebuild the trans myself. Vehicle is a 2008 Silverado 1500 single cab short bed Around 700rwhp. Coming off an alleged freshen up the transmission was still overheating so I’m trying to diagnose/resolve that issue as well as build it back better than it was. It has an ATI Vasco input(I was told also intermediate shaft) and an ATI billet forward hub. Shift kit is transgo HD2.



so this is the bottom friction/steel in the overrun clutch

notching in the 4th housing

p

snap ring seems to be rolled upward

So obviously there’s an issue here but I’m not sure what caused it. I know there was a ridiculous amount of front end play. I didn’t put my dial on it but there was easily 1/4”-3/8” of input shaft play(that includes up to snap ring)


My next question is about the HD2. I know it is not ideal but what are my options now? I have a call into CK but have not heard back yet. I would rather not buy a new VB but will to make it right. One issue is the drilled across the partition and I’m not sure if this will definitely cause an issue. I definitely want to internally dual feed but confused on what direction to go already having the HD2. It does have the pressure relief setup that I’m sure I’m supposed to plug

So I will start with this and see what feedback I receive. I have all the parts I believe for a solid rebuild and basically using all the advice I’ve read from @clinebarger that I could find! Thanks

 

[michaelluscher]

@clinebarger is our resident 4lslippy expert

/s

 

[xgmad]

Something in the torque converter is going wrong. Probably a negative clearance when the torque converter was rebuilt with lower clearance clutch disks instead of using original clearance clutches but I could be wrong.

This caused the torque converter to overheat and then raised overall trans temp, again, I could be wrong but may be the issue here.

 

[xgmad]

So you may want to either rebuild the torque converter yourself (need alot of equipment) or buy your preferred torque converter on the internet or somewhere.

But again, I could be wrong. @clinebarger is the supreme leader when it comes to transmissions.

 

[Rsoup]

Yea, very possible. Converter is at FTI now just waiting to hear from them once they crack it open. The Tcc is actually what caused the issue that required the most recent rebuild

 

[clinebarger]

The Overdrive Carrier/Overrun Hub was not fully splined into the Overrun Friction Internal drive tangs.....You can see the wear marks on the internal drive tangs of the half smoked friction.

As the Overrun Clutch HAS TO overrun in 4th/Overdrive....The hub just stripped out the few tangs that were engaged to the Overrun Hub.

When you put it in D3/D2/D1.....The Overrun Clutch came on & applied cockeyed thus deforming the clutch snap ring.

 

[clinebarger]

I use Circle D on all my higher HP stuff.

 

[Rsoup]

The Overdrive Carrier/Overrun Hub was not fully splined into the Overrun Friction Internal drive tangs.....You can see the wear marks on the internal drive tangs of the half smoked friction.

As the Overrun Clutch HAS TO overrun in 4th/Overdrive....The hub just stripped out the few tangs that were engaged to the Overrun Hub.

When you put it in D3/D2/D1.....The Overrun Clutch came on & applied cockeyed thus deforming the clutch snap ring.

makes sense now! would this cause the overheating issue? It came up to temp normally then would just take off from about 180° and hit 230+ before you could find a place to pull over

I use Circle D on all my higher HP stuff.

yea the FTI was in there when I bought the truck so I never wanted to spend the money on a new one but maybe I should have
thanks

 

[clinebarger]

The 4th Steels beating up the 4th Clutch Housing was caused by the mechanical bind in 4th caused by the unlaced Overrun Friction......Until the internal drive tangs stripped.

I bet it did like to overheat!!

 

[clinebarger]

Build tip......Leave the 4th Frictions & Steels out 'til after the Input & Overdrive Carrier are seated in the Forward Drum. What most likely happened was the builder tried to lace in the 4th Clutch Frictions while installing Input & Overdrive Carrier which can EASILY unlace the first Overrun Friction.

 

[Rsoup]

Build tip......Leave the 4th Frictions & Steels out 'til after the Input & Overdrive Carrier are seated in the Forward Drum. What most likely happened was the builder tried to lace in the 4th Clutch Frictions while installing Input & Overdrive Carrier which can EASILY unlace the first Overrun Friction.

Great tip thanks! Any thoughts on keeping or modifying the HD2 and should I definitely get a new 4th housing?

 

[clinebarger]

I would replace the 4th Clutch Housing, But I'm not saying it wouldn't still function.

The HD-2's sole function is to dual feed the Direct Clutch without disassembling the unit, Might as well internally dual feed while it's apart.

You can tap the pressure relief hole that was drilled in the VB & plug it with a set screw.

 

[Rsoup]

Hey @clinebarger, since dura bond bushings are impossible to find, are the 03131BRS bronze bushings an acceptable replacement for the sungear and overrun clutch bushings? Thanks

 

[clinebarger]

Aftermarket bushing quality is all over the map, Good luck.

 

[Rsoup]

So thanks for all the help so far! Hopefully this will be my last question. So I’m finishing up the build and seem to have maybe hit a snag doing the front end play.

So when running a straight edge across the pump mounting surface, I have about .040” of clearance to the overrun thrust washer. Front end play is .060”. Is this an indication that I’ve made a mistake somewhere in the stack up?

I’ve ordered the .078” forward drum thrust washer. Is this as simple as using that and a thicker overrun thrust washer? The current one measures .090”. How thick can I go here? Thanks

 

[Rsoup]

Never mind I got it dialed in! .78 and .107 got it perfect!